(1) Field of the Invention
The present invention relates to a method of and an apparatus for generating an assembly view from design drawing data by a CAD (computer-aided design) system, and more specifically, to a method of and an apparatus for generating an assembly view of a three-dimensional body composed of a plurality of parts.
(2) Description of the Related Art
A CAD system has become indispensable in a design job to cope with complicated design specifications as well as to effectively carry out a design and drafting job, shorten a design period and simplify jobs accompanying with design. As industries are sophisticated, the function of the CAD system and the field to which the CAD system is applied are enlarged and the CAD system will be hereinafter more and more required to strongly associate with other departments such as, for example, a manufacturing department in addition to a design department.
A product is specifically represented by means of three kinds of views, i.e., a front view, a side view and a plan view at the step of design and the three kinds of views serve as a base in design job. The three kinds of views are generated using various function of a CAD system such as, for example, a drafting function, or diverting and editing existing drawings stored in a data base and then output as drawings. Although the three kinds of views are two-dimensional design drawings, a figure of an image near to the configurational characteristics of an actual body can be generated by three-dimensionally representing the three kinds of views using a three-dimension converting function.
A product designed by a designer is mainly represented by three kinds of views, the three kinds of views cannot be easily understood by staffs of other departments such as, for example, a product planning department which is not related to a design job and a service department which carries out maintenance of products. As described above, it is difficult to cause persons who are not accustomed to the three kinds of views to intuitively understand the image of a product from the three kinds of views.
To cope with this problem, conventionally, there is provided an assembly view of a designed product which is viewed from an optional direction of the product to permit the product to be intuitively understood, in addition to three kinds of views. Since the generation of the assembly view is usually ordered to a technical illustrator or the like, however, it is very expensive and the preparation of it needs a long period of time. Further, since the assembly view is drawn by the technical illustrator by hand based on three kinds of views, it is not of high precision.